Pressure support induced CAs -- Diamox ? Other solutions ?

[dcg494]

Hi all, has anyone successfully tried diamox for centrals ? Took it a few nights and it seems to reduce CAs but I always seem to get joint pain and fatigue from it the next day.

Why I'm asking : Got a bipap about a month ago, and still trying to dial in the settings. I need more IPAP but have reached a limit with aerophagia. Only way to go up with IPAP is to lower the EPAP and go up with pressure support (PS).

I'm already at PS 4 and get ~1CA/hr, and with PS 4.5, CAs will go up -- it's even hard to fall asleep with PS = 4.5, as my breath stops on the threshold of sleep and wakes me up.

So I'm trying to find a way to reduce the CAs and get PS up further. Any ideas ?

Thanks everyone!

[Pugsy]

So how much do the centrals increase with the use of more PS?

I think in your last thread I already told you that

You may have to decide which is more important...lower AHI or avoiding the aerophagia monster...and making a compromise.

People might want to review prior discussion to help with context here.
viewtopic/t172284/Complicated-case--hel ... other.html

I am not convinced that the centrals are caused by an increase in PS in your case.
I would want to see some of those centrals close up to know for sure they were real and not post arousal centrals.
Did I ever point you to the crash course in learning how to identify asleep flagged events from awake flagged events?
http://freecpapadvice.com/sleepyhead-free-software
Watch all the videos.

[dcg494]

Thanks Pugsy! Actually, yes, for a lot of the CAs it looks like they're preceded by a FL, H, or multiple UFs. Posting one here, though a lot are more dramatic than this and some definitely seem like arousal-related CAs. What do you think from this graph ?

Sorry if I posted unnecessarily, just always get stuck and racking my brain on the next possible step. In any case thanks for the quick answer as always.

I'll try PS 4.5 and see how I respond, it just is very hard to fall asleep w it.

[Pugsy]

This last CA is a bit iffy IMHO. Can't always tell as you have learned. Might help to be more definitive about the iffiness of of it we saw more of the breathing pattern preceding it.
To me it leans more to not being real because of the small breaths preceding the flag. Especially the little bump right before the flag.
There's an effort to breathe there and with real centrals there is no effort.
I would tend to call this one probably an OA or hyponea mislabeled but that's an iffy guess.

What is your number one goal here? To me it has to be sleep quality because if you can't get good sleep then the numbers don't matter much do they?

If you can't sleep decently because of discomfort then what good is killing off more of the apnea events with more pressure?

Play with the more PS (if that is what you wish to try) but bear in mind that the lowering of EPAP to attain the ability to increase the PS may result in allowing more obstructive stuff to happen.
If PS of 4.5 is what you want to try and you are having difficulty adjusting to and relaxing to it to fall asleep....do it while watching TV or reading a book so that you get more used to it and aren't under the gun to fall asleep.

[dcg494]

Thanks Pugsy, posting here two more pics that are pretty typical and seem to appear a lot. INterestingly they're often preceded also by a large inhale/exhale, which made me think I was flushing out too much CO2 leading to the CAs.

If mislabeled, do you think these are obstructive or hypopnea ? They look more obstructive don't they ?

My obstructive events index is always <0.1, even with a very low epap, but if these are mislabeled obstructives, then I need to be careful with lowering epap more..

Good idea on getting used to higher PS while doing other stuff, will try that now in fact (;

[Pugsy]

I think those last 2 CAs are probably post arousal and not real.
You don't look like you were asleep when they got flagged.
Plus the line preceding the flag isn't flat...it's bumpy which means there was some effort to breathe.
Look at the breaths before the flag....they aren't smooth and regular..instead they are choppy and more like some sort of arousal happened (you may or may not remember it) and then the flagged CA was probably a post arousal SWJ central or obstructive but not real because you weren't totally asleep preceding the flag.

Look at this guy's flow rate...different machine and software but it let's you look at the flow rate with the big picture.
This guy doesn't have OSA. In fact his in lab sleep study without cpap he came home with an AHI of less than 1.0.
He does have a lot of spontaneous arousals (no known cause) and crappy sleep in general from all the arousals but pretty much all of his flagged events aren't real. They are post arousal SWJ events.

I think you can better see the asleep breathing vs awake/arousal breathing when looking at the big picture.
BTW I did run all these examples by a sleep tech to make sure I wasn't misinterpreting things. He agreed with me. 95% of the flagged events were SWJ crappy sleep flags.

[jnk...]

hard to fall asleep with PS = 4.5, as my breath stops on the threshold of sleep and wakes me up.

I am not anywhere near as experienced as the other posters, but what you describe would tend to make me want to lower PS just a hair and increase min EPAP just a hair, if it were me, with my body/brain status.

I found that when I was using bilevel, the little bit of extra CO2 washout from a high-ish PS was enough to increase the length of the natural pause in breathing when I was transitioning from wake to sleep. That allowed just enough more time for airway instability to occur and cause me to be jarred awake with the hypnic/hypnagogic jerks from heck. For me, lowering PS a bit (for a touch more CO2 stability) and increasing EPAP a bit (for a touch more airway stability) lessened the frequency of those. But I realize that my experience may not be common or standard for others.

I'm trying to find a way to reduce the CAs and get PS up further.

Those may be opposite goals, since upping PS can be the source of further (mostly harmless but highly irritating) CAs for some. A few weeks of comparisons at different PS settings can sometimes establish that fact definitively--but not always, since the body tends to adapt over time and its needs and expectations for breathing and sleep can be a moving target.

Again, take my observations with a grain of salt, since my experiences may reflect my status as a rare subset of an nonstandard phenotype. And Pugsy and Palerider have much more experience with normal people than I do.

[Pugsy]

These are most likely the real deal OAs.
See how the flow rate is nice and smooth and regular before and after the flags? Not choppy or spiky.


I don't have a central flag handy that is real and I am short on time today to go poking through all my reports to find one but later if I have time I will see if I can spot one. Mostly any centrals/CAs I get flagged are SWJ post arousal centrals and it's real obvious.

[Pugsy]

I did a quick look through some of my reports. I rarely get a real looking central. I probably turned over in bed and held my breath while turning.
Here's what mine normally look like.

arousal central.JPG

and here are a couple that look more real to me

maybe central.JPG

[Pugsy]

Maybe if you better prevented the obstructive stuff from happening you would have less arousals and thus less chance of post arousal centrals getting flagged.
Just a thought...working from the aspect that the centrals you are seeing aren't related to PS but instead related to crappy sleep from arousals from the obstructive stuff going on.

[dcg494]

Thanks Pugsy and Jnk, really helpful. Jnk you mention an entirely new consideration, a lengthened pause in breathing b/w transition states which includes when arousals happen I assume.

Pugsy, really interesting example -- only I can't see the pictures you uploaded for some reason. I think the links may be outdated, probably not possible to re-upload ?

So these could be SWJ or they could be post-arousal pauses in breathing, right ? I'm guessing they're more likely to be OAs because they're often 20 seconds or longer.

I'll post a final example, pause of over 30s. Preceded by a long inhald also, which is pretty common when looking at these. This is why I thought they were CAs, thinking the long inhale exhale flushed out CO2 leading to a CA.

And the little bumps coincide with the pressure pulses, so I though that's where those are coming from.

[jnk...]

entirely new consideration, a lengthened pause in breathing b/w transition states

It was a consideration for me, but may not need to be a consideration for most. For me, the sleep-wake junk that can generally be ignored by most people was a primary issue, because it prevented my being able to fall asleep smoothly. My brain/nervous system was touchy about it all because it knew something different was going on but it couldn't figure out what. My OSA had been so bad that my system forgot what normal transitions between stages were supposed to be. It was extreme. It took a while for me to figure out how to help my body/brain get a handle on it. But as I said, I think very few people experience the sorts of things I experienced, and that is why SWJ should generally be ignored as something insignificant for most when making pressure choices. I may be the exception that proves the rule. But your wording sounded familiar enough to me that I thought I should mention my experience to you.

[Pugsy]

The links I just did are fresh...they should show up. Give them a bit of time...they are in the forum as attachments and I can see them fine. Sometimes images linked to the forum storage are slow to load. They are fresh though...just now did them.


Pressure pulses won't impact the breath flow rate graph. They are little blips of pressure on the pressure graph.
We see pressure pulses when the machine can't decide what to call the reduction in breathing.
Those little blips are breathing efforts...probably why the machine is doing the pressure pulse to try to figure out what is going on.
There's an obvious big deep breath preceding those events....arousal...so those events probably are post arousal SWJ.